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Hiroki Tsukamoto Sueo Hisada Sansei Nishibe David G. Roux John P. Rourke 《Phytochemistry》1984,23(3):699-700
Esculetin and scopoletin were isolated from the bark of Olea africana while isoscopoletin and scoparone were isolated from the bark of Olea capensis. The distribution of these coumarins in Olea species from South Africa is described. 相似文献
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Enzymes for the methylation of 1hydroxycanthin-6-one and a series of coumarins have been isolated from Ailanthus altissima cell suspension cultures. The coumarin methyltransferases methylate aesculetin to scopoletin and isoscopoletin, but not scopoletin, to scoparone. Fraxetin was methylated to isofraxidine but not to fraxidine and only fraxidine was methylated to 6,7,8-trimethoxycoumarin. These enzymes were studied throughout the culture growth cycle with two cell lines: 1, which produced 1-methoxycanthin-6-one as the major alkaloid and 2, in which canthin-6-one was the major alkaloid.Abbreviations UV
ultraviolet
- DEAE
diethylaminoethyl
- dw
dry weight
- MS
mass spectrometry
- NMR
nuclear magnetic resonance
- TLC
thin layer chromatography 相似文献
4.
《Life sciences》1993,53(25):PL421-PL426
Coumarin derivative, scoparone (6,7-dimethoxycoumarin), is regioselectively O-demethylated into isoscopoletin (I) and scopoletin (S). This oxidation is inversely influenced by cytochrome P-450 inducers in the rat such as 3-methylcholantrene (3-MC) and phenobarbital (PB). The I/S ratio is higher than 1.5 with 3-MC treatment whereas it is lower than 0.5 with PB treatment. With regards to this contrasting effect, it gas been suggested that the I/S ratio should be useful to differemtiate between the effects of these types of inducers. We studied the consequences of in vivo PB and 3-MC treatment on scoparone biotransformation in guinea pig and rabbit. In these two species, at the basal state, scoparone biotransformation was enhanced in comparison to the rat. Moreover, in these untreated animals, two other metabolites were formed. After 3-MC or PB treatment, scoparone metabolism is, in contrast to the rat, inappropriate to differentiate between the P-450 profile of other animals. 相似文献
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O-Methylated flavonoids are biosynthesized by regioselective flavonoid O-methyltransferases (OMTs), which may account for the limited number of naturally occurring flavonoids in nature. It was previously shown that poplar POMT-7 regioselectively methylates the 7-hydroxyl group of flavones, whereas rice ROMT-9 regioselectively methylates the 3'-hydroxyl group of the substrate. We co-expressed both OMT genes (POMT-7 and ROMT-9) in E. coli and carried out biotransformation experiments of some flavonoids with the transformed E. coli strain. Contrast to the predicted regioselectivity of both POMT-7 and ROMT-9, unexpected methylation reaction products, i.e. 3',4'-O-methylated flavonoids, in addition to the predicted ones, were obtained with luteolin (5,7,3',4'-tetrahydroxyflavone) and quercetin (3,5,7,3',4'-pentahydroxyflavone) as substrates. Reactions using the 3'-O-methyl derivative of luteolin and quercetin by POMT-7 revealed that the enzyme has altered its regioselectivity from the 7- to the 4'-hydroxyl groups. These results are discussed in terms of molecular modeling of POMT-7 in relation to its methyl donor. 相似文献
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R P Meyer C E Hagemeyer R Knoth G Kurz B Volk 《Biochemical and biophysical research communications》2001,285(1):32-39
Regioselective 7-demethylation of scoparone is regularly employed as an indicator of phenobarbital-like induction of rat liver cytochrome P450 isoform CYP2B1, e.g., by the antiepileptic drug phenytoin. After induction with phenobarbital and phenytoin, a new reaction sequence catalyzed by Cyp2c29 was identified in mouse liver microsomes. Cyp2c29-dependent 6-demethylation of scoparone resulted in the formation of isoscopoletin, an intermediate which is susceptible to further oxidation. This subsequent oxidation was also catalyzed by Cyp2c29 with a K(m) of 30,31 microM and a V(max) of 3,41 microM/min x microM P450, and resulted in the formation of the new metabolite 3-[4-methoxy-p-(3,6)-benzoquinone]-2-propenoate. This novel metabolite is the product of two consecutive oxidation reactions, proceeding over isoscopoletin to a putative lactone which is accessible to immediate hydrolysis, due to the onium character of the ring oxygen. This opening of the lactone ring corresponds to an oxidative hydrolysis. Differential oxidation of scoparone can be used as a sensitive indicator for distinguishing between different cytochrome P450 isoforms. 相似文献
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Ten coumarins and four flavonoids have been isolated from a single collection of Artemesia tridentata ssp. vaseyana (Rydb.) Beetle. The coumarins are 7-methylesculin, esculin, umbelliferone, skimmin, cichoriin, isoscopoletin, scopoletin, scoparon, esculetin and a new natural product, artelin (5,6,7,8-tetramethoxy coumarin). The flavonoids are luteolin, luteolin-7-glucoside, axillarin and eupafolin. 相似文献
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Mulholland DA Langlois A Randrianarivelojosia M Derat E Nuzillard JM 《Phytochemical analysis : PCA》2006,17(2):87-90
Oleanolic acid, scoparone, scopoletin and a novel iridoid derivative, angelone, were isolated from Tachiadenus longiflorus (Gentianaceae). The structure of angelone was determined from NMR data, given as input to the Logic for Structure Determination Programme, and was finally confirmed by comparison of experimental 13C-NMR chemical shifts with those obtained by quantum mechanical calculations. 相似文献
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Soad A.L. Bayoumi Michael G. Rowan John R. Beeching Ian S. Blagbrough 《Phytochemistry》2010,71(5-6):598-604
A phytochemical analysis of cassava (Manihot esculenta Crantz) fresh roots and roots suffering from post-harvest physiological deterioration (PPD) has been carried out. The first isolation and identification of galactosyl diacylglycerides from fresh cassava roots is reported, as well as β-carotene, linamarin, and β-sitosterol glucopyranoside. The hydroxycoumarin scopoletin and its glucoside scopolin were identified from cassava roots during PPD, as well as trace quantities of esculetin and its glucoside esculin. There is no isoscopoletin in cassava roots during PPD. 相似文献
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Regioselectivity of 7-O-methyltransferase of poplar to flavones 总被引:1,自引:0,他引:1
POMT-7, an O-methyltransferase from poplar (Populus deltoids) was used to modify a variety of flavonoid compounds. POMT-7 was able to transfer a methyl group to several flavonoids containing a C-7 hydroxyl group. However, POMT-7 showed a higher affinity toward flavonol and flavone such as apigenin, kaempferol, luteolin, and quercetin than flavanone and isoflavone. Based on comparison of HPLC retention times with authentic compounds and corresponding nuclear magnetic resonance spectroscopy data, the methylation position of the reaction products was determined to be at the hydroxyl group of C-7. Biotransformation kinetics indicated that the enzyme converted more than 80% of the apigenin, kaempferol, luteolin and quercetin substrates, which were added at concentration of 70 microM, into corresponding 7-methoxy compounds within 24 h. 相似文献
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《Phytomedicine》2014,21(3):240-246
BackgroundCoumarins, also known as benzopyrones, are plant-derived products with several pharmacological properties, including antioxidant and anti-inflammatory activities. Based on the wide distribution of coumarin derivatives in plant-based foods and beverages in the human diet, our objective was to evaluate both the antioxidant and intestinal anti-inflammatory activities of six coumarin derivatives of plant origin (scopoletin, scoparone, fraxetin, 4-methyl-umbeliferone, esculin and daphnetin) to verify if potential intestinal anti-inflammatory activity was related to antioxidant properties.MethodsIntestinal inflammation was induced by intracolonic instillation of TNBS in rats. The animals were treated with coumarins by oral route. The animals were killed 48 h after colitis induction. The colonic segments were obtained after laparotomy and macroscopic and biochemical parameters (determination of glutathione level and myeloperoxidase and alkaline phosphatase activities) were evaluated. The antioxidant properties of these coumarins were examined by lipid peroxidation and DPPH assays.ResultsTreatment with esculin, scoparone and daphnetin produced the best protective effects. All coumarin derivatives showed antioxidant activity in the DPPH assay, while daphnetin and fraxetin also showed antioxidant activity by inhibiting lipid peroxidation. Coumarins, except 4-methyl-umbeliferone, also showed antioxidant activity through the counteraction of glutathione levels or through the inhibition of myeloperoxidase activity.DiscussionThe intestinal anti-inflammatory activity of coumarin derivatives were related to their antioxidant properties, suggesting that consumption of coumarins and/or foods rich in coumarin derivatives, particularly daphnetin, esculin and scoparone, could prevent intestinal inflammatory disease. 相似文献
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Jim Kawabata Yukiharu Fukushi Satoshi Tahara Junya Mizutani 《Bioscience, biotechnology, and biochemistry》2013,77(3):713-717
Three novel sesquiterpene alcohols, shizuka-acoradienol (2), shizukafuranol (3) and shizukol-idol (4), were isolated from Chloranthus japonicus Sieb. (Japanese name: Hitori-shizuka, Chloranthaceae). Their structures were elucidated on the basis of their physicochemical properties and some chemical reactions. Furanodienone (5), scopoletin (6a) and isoscopoletin (6b) were also isolated from this plant. 相似文献
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A phytochemical analysis of the bark of the Malagasy Cedrelopsis rakotozafyi Cheek and Lescot (Rutaceae) yielded the novel 8-hydroxy-7-methoxy-6-(2R-hydroxy-3-methylbut-3-enoxy)-2H-1-benzopyran-2-one, and 7-hydroxy-6-(2R-hydroxy-3-methylbut-3-enoxy)-2H-1-benzopyran-2-one, 5,6,7-trimethoxy-2H-1-benzopyran-2-one, scoparone, scopoletin, lupeol and β-amyrin. The placement of Cedrelopsis within the Rutaceae is supported phytochemically by the typically Rutaceous coumarins isolated. 相似文献
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《Process Biochemistry》2010,45(5):655-659
The potential applications of glycosyltransferases in glycoconjugate synthesis have attracted considerable interest from the biotechnology community in recent years. In this work, we present a novel glucosyltransferase from Catharanthus roseus cell cultures. The enzyme was purified to one spot in SDS-polyacrylamide gel electrophoresis, and its molecular weight was about 51 kDa. The optimum temperature was 35 °C, and the optimum pH was 7.6. Sodium ion has weak effect on enzyme activity, whereas divalent ions inhibit enzyme activity strongly. The Km values were 0.112, 0.077, 0.064 and 1.0 mM for scopoletin, 5,7-dihydroxyflavone, 5,7-dihydroxyflavanone and UDPG, respectively. Substrate screening with the purified enzyme was performed against a range of phenolic compounds using UDPG as sugar donor. The enzyme showed activity towards a number of coumarins including umbelliferone, scopoletin, isoscopoletin and esculetin, and flavonoids including a flavone, a flavanone and chalcones. No activity was detected with compounds characterized by a single aromatic ring, i.e. simple and acidic phenols. The substrate specificity and the regioselectivity suggest enzyme structural features that are different from those of other glucosyltransferases. 相似文献
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Arras G Dhallewin G Petretto A Marceddu S Loche M Agabbio M 《Communications in agricultural and applied biological sciences》2005,70(3):391-397
Health and environmental concerns have point out the need to improve or change several manufacturing steps in the food chain. In this context particular attention should be given to the technologies involved in fruits and vegetables production. Nearly all fresh fruit and vegetables are subjected to different periods of storage and/or shelf-life before of their consumption. This implies the need to protect the commodities from microbial spoilage. Some Citrus species (e.g. lemon and grapefruit) may be stored for several months before consumption and then post-harvest treatments are essential to contain green (Penicillium digitatum) and blue (P. italicum) moulds. Alternative approaches to chemicals usually have a lower efficacy in containing rots but fulfill the consumer's expectation. Among the alternative strategies, the improvement of host natural resistance is promising. In this regard, we report some results concerning the use of biotic (yeast) and abiotic agents as inducers of phytoalexin (i.e. scoparone and/or scopoletin) accumulation in Citrus rind and its importance in the control of fungal decay. In all experiments the inducers were applied on fruits before or 24 h after inoculation with P. digitatum and the rot severity was monitored 7 days later. The accumulation of phytoalexins was monitored according to a standard methodology by HPLC. In all experiments a positive correlation was found between increase of the phytoalexin scoparone in host tissue and reduction of decay. 相似文献
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Bong Gyu Kim Yoon Jung Lee Younghee Park Yoongho Lim Joong-Hoon Ahn 《Journal of Plant Biology》2006,49(1):55-60
Enzymatic O-methylation, catalyzed by S-adenosyl-L-methionine (SAM)-dependent O-methyltranferases (OMTs), is a ubiquitous
reaction, occurring in almost all living organisms. Plant OMTs are involved in the methylation of secondary metabolites, including
phenylpropanoid and flavonoid compounds. Here, we used RT-PCR to isolate and characterizePOMT-2 fromPopulus deltoides. This OMT comprises a 1095-b open reading frame that encodes a 39.7-kDa protein. BLAST results showed 87% identities to an
OMT fromPrunus dulcis and a caffeic acid OMT fromRosa chinensis. POMT-2 was expressed inEscherichia coli as a glutathione S-transferase fusion protein, and was purified by affinity chromatography. POMT-2 transferred a methyl group
of SAM to caffeic acid and 6,7-dihydroxyflavone, but showed low activities toward quercetin and kaempferol. According to itsin vitro substrate preference and composition of phenolic compounds in poplar, thein vivo function of POMT-2 is probably the methylation of caffeic acid and an involvement in lignin biosynthesis. 相似文献
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Scopoletin is one of the phytoalexins in tobacco. Cells of the T-13 cell line (Nicotiana tabacum L. Bright Yellow) accumulate a large amount of scopoletin, also known as 7-hydroxy-6-methoxycoumarin, as a glucoconjugate, scopolin, in vacuoles. We report here the molecular cloning of glucosyltransferases that can catalyze the glucosylation of many kinds of secondary metabolites including scopoletin. Two cDNAs encoding glucosyltransferase (NtGT1a and NtGT1b) were isolated from a cDNA library derived from the tobacco T-13 cell line by screening with heterologous cDNAs as a probe. The deduced amino-acid sequences of NtGT1a and NtGT1b exhibited 92% identity with each other, approximately 20-50% identities with other reported glucosyltransferases. Heterologous expression of these genes in Escherichia coli showed that the recombinant enzymes had glucosylation activity against both flavonoids and coumarins. They also strongly reacted with 2-naphthol as a substrate. These recombinant enzymes can utilize UDP-glucose as the sugar donor, but they can also utilize UDP-xylose as a weak donor. RNA blot analysis showed that these genes are induced by salicylic acid and auxin, but the time course of the expression was different. This result is similar to the changes in scopoletin glucosylation activity in these tobacco cells after addition of these plant growth regulators. These results might suggest that one of the roles of the products of these genes is scopoletin glucosylation, in response to salicylic acid and/or auxin, together with the other glucosyltransferases in tobacco cells. 相似文献
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Johann S Oliveira VL Pizzolatti MG Schripsema J Braz-Filho R Branco A Smânia Jr A 《Memórias do Instituto Oswaldo Cruz》2007,102(6):681-685
Antibacterial and antifungal properties of wax and hexane extracts of Citrus spp. peels were tested using bioautographic and microdilution techniques against three plant pathogenic fungi (Penicillium digitatum, Curvularia sp., and Colletotrichum sp.), two human pathogens (Trichophyton mentagrophytes and Microsporum canis), and two opportunistic bacteria (Escherichia coli and Staphylococcus aureus). Two polymethoxylated flavonoids and a coumarin derivative, were isolated and identified from peel extracts, which presented antimicrobial activity especially against M. canis and T. mentagrophytes: 4',5,6,7,8-pentamethoxyflavone (tangeritin) and 3',4',5,6,7,8-hexamethoxyflavone (nobiletin) from C. reticulata; and 6,7-dimethoxycoumarin (also known as escoparone, scoparone or scoparin) from C. limon. 相似文献